FRET studies in mesoscopic antenna materials

This spectroscopy study was carried out in Newcastle University, using a time-resolved fluorimeter acquired with fundings from the EPSRC grant "MESO-FRET" (EP/P015395/1) and from the Newcastle SAgE Faculty. The data refer to the optical properties of two "antenna" systems based on mesoporous silica scaffolds incorporating an iridium(III) complex as energy donor and a bodipy dye as acceptor. When a 1% loading of donors and acceptors is used into silica, the non-radiative deactivation processes are considerably hindered, as demonstrated by an increase in the excited state lifetime compared to solvated molecules. Average FRET efficiencies range from 24% in the low loading sample to 76% at high loadings (5%), with estimated donor-acceptor distances of 5.7 nm and 3.9 nm, respectively. This comes as a result of the increased concentration of the two dyes, which are localised at specific sites into the silica and whose incorporation does not alter the mesoporous order and the morphology of the material.